From fcd366b95e6e356ae5069753938988b6c6286fa8 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 10 Oct 2024 11:23:38 -0700 Subject: [PATCH] KVM: x86: Don't fault-in APIC access page during initial allocation Drop the gfn_to_page() lookup when installing KVM's internal memslot for the APIC access page, as KVM doesn't need to immediately fault-in the page now that the page isn't pinned. In the extremely unlikely event the kernel can't allocate a 4KiB page, KVM can just as easily return -EFAULT on the future page fault. Suggested-by: Paolo Bonzini Signed-off-by: Sean Christopherson Tested-by: Dmitry Osipenko Signed-off-by: Paolo Bonzini Message-ID: <20241010182427.1434605-37-seanjc@google.com> --- arch/x86/kvm/lapic.c | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 20526e4d6c62..65412640cfc7 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2647,7 +2647,6 @@ void kvm_apic_update_apicv(struct kvm_vcpu *vcpu) int kvm_alloc_apic_access_page(struct kvm *kvm) { - struct page *page; void __user *hva; int ret = 0; @@ -2663,17 +2662,6 @@ int kvm_alloc_apic_access_page(struct kvm *kvm) goto out; } - page = gfn_to_page(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT); - if (!page) { - ret = -EFAULT; - goto out; - } - - /* - * Do not pin the page in memory, so that memory hot-unplug - * is able to migrate it. - */ - put_page(page); kvm->arch.apic_access_memslot_enabled = true; out: mutex_unlock(&kvm->slots_lock); -- 2.50.1